I installed spark and tried connecting it to the OpenFire server and even that isn't working it gives error saying "Can't connect to server: invlid name or server not reachable" :-|

I tried with user defined in "User/Group" page and I am able to ping my OpenFire server from that machine and moreover I am able to register SIP Softphone to the Asterisk server running on same machine as openfire ... so finding server should not be an issue.